1. Field of the Invention
The present invention relates to an electronic computer suitable for a graphical function calculator or the like and a method of controlling the same.
2. Description of the Related Art
Some of the known electronic computers, including scientific electronic calculators, are so-called graphical function calculators which display a graph corresponding to a function expression input by the user. When the user inputs a function expression by operating the input keys and then gives an instruction to draw a graph by operating a specific key, the graphical function calculator draws and displays a graph of the function on the orthogonal coordinate axes.
Some graphical function calculators have a trace function. The trace function is to move a pointer on the function graph according to the key operation and display the coordinate values of the position of the pointer on the graph at the time.
Concerning the graphical function calculator with a trace function, the technique for enabling two trace pointers to be displayed at the same time has been considered (e.g., Jpn. Pat. Appln. KOKAI Publication No. 2001-216273).
Conventional graphical function calculators are incapable of analyzing the relationship between two points on a graph. The same holds true for the technique disclosed in the above patent document. That is, the relationship between two points on a graph was incapable of being analyzed variously.